For installing light pillars, such as fence posts, it is used a zinc-coated steel anchor consisting of a wedge-shaped ground-protruding portion and a welded socket on its top, wherein the pillar is inserted into the socket. Posts of different diameters require different sizes of ground anchors. A benefit of this type of ground anchor is its simple, affordable structure and ease of installation. A drawback, however, is its lack of adjustability: each standard size post requires its own fixed anchor/socket combination. Furthermore, this type of ground anchor must be rammed into the ground completely vertically and precisely in the right point. Otherwise the Fence post may be skewed and displaced from the right point. It is practically impossible to align consecutive posts exactly.
Finnish patent No. 115988 describes a ground anchor where a post socket is bolted on a flange welded to the top of the wedge part. Before the bolt connection is tightened, the position of the socket in relation to the flange can be adjusted owing to slots located on the bottom of the flange and the socket. This enables horizontal adjustment of the flange, making it easier to make a straight line of fence posts. A drawback is that when the wedge is slightly tilted during ramming, the post mounted into the socket will also be tilted.
Applicant's patent application U.S. Ser. No. 13/359,757 presents a significant improvement in the adjustability. It describes a ground anchor with two parallel grooves located on a top plate of the wedge part. There are two L-shaped brackets attached to the end plate. The flange of the L-bracket that is against the top plate has a elongated slot parallel to the flange crease. A fence post is inserted between the upwards-pointing flanges of the L-brackets. Bolts are inserted first through the slots in the top plate and through the slots in the brackets and the nuts are lightly tightened. The slots enable free movement of the brackets on the top plate. This subsequently enables the L-brackets to be adjusted in order to achieve a direct post line, after which the nuts are tightened.
A benefit of the solution described in that patent application is that the adjustable distance between the L-brackets enables the same ground anchor to be used for posts of various sizes. Additionally, if the ground anchor is tilted during ramming, as is the case almost every time, the tilting can be compensated by, for example, bending the upwards-protruding flanges of the brackets with a sledge hammer to straighten the post installed between the brackets. The flanges can also be straightened by bending the fence post installed between the brackets. In practice, however, bending the flanges is not easy, particularly if the L-brackets are made of thick steel plate. This may result in an uneven bending of the flanges, making it nearly impossible to make the flanges parallel to each other.
In fence construction it happens very often that the ground anchor hits a rock during ramming which causes tilting of the anchor. This, subsequently, results in a tilted post. Most commonly used ground anchors make it impossible or, in case a ground anchor of U.S. Ser. No. 13/359,757 is used, difficult to correct the tilt.
An objective of this invention is to devise a ground anchor which is free of the disadvantages that the known ground anchors have. More precisely, the objective is to devise an adjustable ground anchor which not only allows horizontal adjustment of the position of a post prior to its installation, but which enables compensation of the tilting caused by a tilted ground anchor so that a fence post becomes completely upright.